Vacuum cleaner

ABSTRACT

Provided is a vacuum cleaner. The vacuum cleaner includes a cleaner body including a suction motor for generating a suction force, a suction part communicating with the cleaner body to suction air and dusts, at least one battery disposed in the cleaner body or suction part to supply a power to the suction motor, and a controller controlling an operation of the suction motor. The controller control an output of the suction motor according to a voltage of the at least one battery.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/721,711, filed May 26, 2015, which claims priority under 35U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No.10-2014-0077107 (filed on Jun. 24, 2014), which is hereby incorporatedby reference in its entirety.

BACKGROUND

In general, vacuum cleaners are devices that suction air containingdusts by using a suction force generated by a suction motor mounted in amain body to filter the dusts in the main body.

Vacuum cleaners are classified into manual cleaners and automaticcleaners. The manual cleaners are cleaners that are used for directlyperforming cleaning by a user, and the automatic cleaners that travel byoneself to perform cleaning.

The manual cleaners may be classified into a canister type cleaner inwhich a suction nozzle is provided separately with respect to a mainbody and connected to the main body by using a connection tube and anupright type cleaner in which a suction nozzle is coupled to a mainbody.

A power cord outlet of a cleaner is disclosed in Korean PatentPublication No. 10-2006-0118796 (Published Date: Nov. 24, 2006).

According to the prior document, since a cord reel assembly is providedin a main body, and a power cord is connected to a socket, the main bodymay receive a power.

In the prior document, since a cleaner receives a power through the cordreel assembly, the cleaner may move by only a distance corresponding toa length of the cord wound around the cord reel assembly when thecleaner performs cleaning.

SUMMARY

Embodiments relate to a vacuum cleaner.

In one embodiment, a vacuum cleaner includes: a cleaner body including asuction motor for generating a suction force; a suction partcommunicating with the cleaner body to suction air and dusts; at leastone battery disposed in the cleaner body or suction part to supply apower to the suction motor; and a controller controlling an operation ofthe suction motor, wherein the controller control an output of thesuction motor according to a voltage of the at least one battery.

In another embodiment, a vacuum cleaner includes: a cleaner body; asuction part communicating with the cleaner body to suction air anddusts; a first battery disposed on the cleaner body or the suction part,the first battery having a first maximum charging voltage; a secondbattery disposed on the cleaner body or the suction part, the secondbattery having a second maximum charging voltage that is less than thefirst maximum charging voltage; a first driving part receiving a powerfrom the first battery; and a second driving part receiving a power fromthe second battery.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features will be apparent fromthe description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vacuum cleaner according to a firstembodiment.

FIG. 2 is a block diagram of the vacuum cleaner according to the firstembodiment.

FIG. 3 is a block diagram of a vacuum cleaner according to a secondembodiment.

FIG. 4 is a flowchart for explaining a method of controlling the vacuumcleaner according to the second embodiment.

FIG. 5 is a perspective view of a vacuum cleaner according to a thirdembodiment.

FIG. 6 is a block diagram of the vacuum cleaner according to the thirdembodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings.

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings that form a part hereof,and in which is shown by way of illustration specific preferredembodiments in which the invention may be practiced. These embodimentsare described in sufficient detail to enable those skilled in the art topractice the invention, and it is understood that other embodiments maybe utilized and that logical structural, mechanical, electrical, andchemical changes may be made without departing from the spirit or scopeof the invention. To avoid detail not necessary to enable those skilledin the art to practice the invention, the description may omit certaininformation known to those skilled in the art. The following detaileddescription is, therefore, not to be taken in a limiting sense.

Also, in the description of embodiments, terms such as first, second, A,B, (a), (b) or the like may be used herein when describing components ofthe present invention. Each of these terminologies is not used to definean essence, order or sequence of a corresponding component but usedmerely to distinguish the corresponding component from othercomponent(s). It should be noted that if it is described in thespecification that one component is “connected,” “coupled” or “joined”to another component, the former may be directly “connected,” “coupled,”and “joined” to the latter or “connected”, “coupled”, and “joined” tothe latter via another component.

FIG. 1 is a perspective view of a vacuum cleaner according to a firstembodiment, and FIG. 2 is a block diagram of the vacuum cleaneraccording to the first embodiment.

Referring to FIGS. 1 and 2, a vacuum cleaner 1 according to the firstembodiment may include a cleaner body 10 and a suction device 20 forguiding air containing dusts into the cleaner body 10.

The suction device 20 may include a suction part 21 for suctioning dustsdisposed on a surface to be cleaned, for example, a bottom surface andconnection parts 22, 23, and 24 for connecting the suction part 21 tothe cleaner body 10.

The connection part 22, 23, and 24 may include an extension tube 24connected to the suction part 21, a handle 22 connected to the extensionpart 24, and a suction hose 23 connecting the handle 22 to the cleanerbody 10.

Also, the vacuum cleaner 1 may further include a dust separation part(not shown) for separating dusts from air suctioned by the suctiondevice 20 and a dust container 110 for storing the dusts separated bythe dust separation part. The dust container 110 may be separablymounted on the cleaner body 10. The dust separation part may be providedas a separate part that is separated from the dust container 110 or beprovided as one module together with the dust container 110.

The vacuum cleaner 1 may include a plurality of driving parts 160 and170 that receive a power to operate.

The vacuum cleaner 1 may further include a plurality of batteries 121and 122 supplying a power for operating the plurality of driving parts160 and 170 and a charger 30 separably connected to the cleaner body 10to charge the plurality of batteries 121 and 122.

The charger 30 may include a power cord 31 connected to a socket and acharger connector 32 connected to the cleaner body 10. Also, the cleanerbody 10 may include a cleaner connector 102 connected to the chargerconnector 32. For another example, the cleaner connector 102 may beprovided on the suction part 102. The cleaner connector 102 may protrudefrom the cleaner body 10 or the suction part 21.

The plurality of batteries 121 and 122 may be disposed on at least oneof the cleaner body 10 and the suction part 21. For example, all of theplurality of batteries 121 and 122 may be disposed on the cleaner body10 or the suction part 21. Alternatively, a portion of the plurality ofbatteries 121 and 122 may be disposed on the suction part 21, and theother portion may be disposed on the cleaner body 10.

The charger 30 may perform rectification and smoothing operations toconvert a commercial AC voltage into a DC voltage. Also, the charger 30may supply the converted DC voltage to the cleaner connector 102. Forexample, the charger 30 may convert the commercial AC voltage into a DCvoltage of about 42.4 V or less to supply the converted DC voltage tothe cleaner connector 102.

Thus, since the DC voltage of about 42.4 V or less is outputted from thecharger connector 32 of the charger 30, there is no problem in usersafety even though an insulation device is not provided to the chargerconnecter 32. Alternatively, the insulation device may be provided tothe charger connector 32.

The plurality of batteries 121 and 122 may include a first battery 121having a first maximum charging voltage and a second battery 122 havinga second maximum charging voltage. Here, the first maximum chargingvoltage is greater than the second maximum charging voltage.

Each of the batteries 121 and 122 may include a plurality of unit cellsthat are connected to each other in series. The plurality of unit cellsmay be maintained and managed to a predetermined voltage by a batterymanagement system (BMS) (now shown). That is, the BMS may allow each ofthe batteries 121 and 122 to output the predetermined voltage. Each ofthe batteries 121 and 122 may be a chargeable and dischargeablesecondary battery.

Although not limited, the first maximum charging voltage may be greaterthan that of about 42.4 V, and the second maximum charging voltage maybe equal to or less than that of about 42.4V. For example, the firstmaximum charging voltage may be above about 84.8 V.

The plurality of driving parts 160 and 170 may include a first drivingpart receiving a power from the first battery 121 and a second drivingpart 170 receiving a power from the second battery 122.

For example, the first driving part 160 may include a suction motor 161that operates until an operation start command is inputted, and anoperation stop command is inputted.

Also, the first driving part 160 may further include a pressing memberdriving part 162 turned on/off by being interlocked with the suctionmotor 161. A pressing member 163 for pressing dusts stored in the dustcontainer 110 may be disposed in the dust container 110. The pressingmember driving part 162 may drive the pressing member 163. However, thepressing member may be omitted in the dust container 110. In this case,the pressing member driving part 162 may be omitted. In thisspecification, the first driving part 160 may be called an always-ondriving part that is driven always.

The second driving part 170 may be called an intermittent driving partthat operates only when a specific condition is satisfied. That is, thesecond driving part 170 may be switched from a turn-on state into aturn-off state or from the turn-off state into the turn-on state whilethe first driving part 160 operates.

Although not limited, the second driving part 170 may include at leastone of a brush driving part 171 for driving a brush 173 disposed on thesuction nozzle 21 and a wheel driving part 172 for driving a wheel 105for moving the cleaner body 10.

In the current embodiment, the suction motor 161 may be, for example, aBLDC motor. Also, the suction motor 161 may have a maximum output ofabout 600 W or more, but is not limited thereto.

When the maximum voltage charged in the battery 121 is below about 42.4V, current of minimum 14.15 A or more has to be applied to operate thehigh-output suction motor 161. As a result, a circuit required foroperating the suction motor 161 may be complicated.

However, in the current embodiment, the high-output suction motor 161may operate by using the voltage charged in the first battery 121, whichhas the maximum charging voltage, of the plurality of batteries 121 and122.

Here, to charge the first battery 121, the cleaner body 10 or thesuction part 21 may further include a booster 140 for receiving a DCvoltage of about 42.4 V or less from the charger 30 to boost thereceived DC voltage and provide the boosted voltage to the first battery121. The booster 140 may include, for example, a boost converter 140 (ora DC/DC converter).

The boost converter may include an inductor, a diode, a capacitor, and aswitching device. Also, the switching device may be quickly andrepeatedly turned on/off by the control of a controller 130 to allow theboost converter to boost an input voltage.

Here, the switching device may include a MOSFET, but is not limitedthereto. For example, the switching device may include a bipolarjunction transistor (BJT) or an insulated gate bipolar transistor(IGBT).

Also, the first and second batteries 121 and 122 may be connected to thecontroller 130. The controller 130 may output a switching signal of theswitching device of the boost converter. Also, the controller 130 maycontrol the first and second batteries 121 and 122 so that a voltage ofthe first battery 121 is supplied to the first driving part 160, and avoltage of the second battery 122 is supplied to the second driving part161.

Thus, the maximum DC voltage outputted from the first battery 121 may beabove about 84.8 V, and the voltage outputted from the first battery 121may be provided to the suction motor 161 by the controller 130. Also,the controller 130 may control an operation of the suction motor 161.

Since a high voltage of about 84.8 V or more is supplied to the suctionmotor 161 in the current embodiment, the suction motor may realize ahigh output. Thus, the suction force of the vacuum cleaner 1 mayincrease to improve cleaning performance.

In the current embodiment, since the first battery 121 is electricallyconnected to the cleaner connector 102, and the first battery 121 hasthe maximum charging voltage of about 84.8 V or more, an isolated boostconverter for electrical insulation of the cleaner connector 102 may beused. The isolated boost converter may be a converter in which aninductor is replaced with a transformer.

For another example, a transformer may be disposed between the boostconverter and the first battery 121.

In this case, the boost converter may primarily boost the output voltageof the charger 30, and the transformer may secondarily boost the outputvoltage of the boost converter.

For another example, the boost converter may boost the output voltage ofthe charger 30, and the transformer may output the same voltage as theoutput voltage of the boost converter. In either case, the first battery121 may have the maximum charging voltage of about 84.8 V or more.

In the case where the transformer is used, the transformer may performthe insulation function regardless of a kind of boost converter. As aresult, the cleaner connector 102 may be insulated.

According to the proposed embodiment, since the suction motor receives apower from the first battery 121 having the high maximum chargingvoltage to operate, the high-output suction motor may be used.

Also, since the voltage of the first battery having the high maximumcharging voltage is supplied to the first driving part, and the voltageof the second battery having the maximum charging voltage less than thatof the first battery is supplied to the second driving part, a chargingtime for each of the batteries may be reduced.

Since the charging time for each of the batteries is reduced, a use timeof the cleaner may increase after each of the batteries is charged once.

FIG. 3 is a block diagram of a vacuum cleaner according to a secondembodiment.

In descriptions of the current embodiment, the same part as that of thefirst embodiment will use the same constitution and reference numeral ofthe first embodiment.

Referring to FIG. 3, a vacuum cleaner 1 according to the currentembodiment may include a charger 30, a booster 140, a battery 123, acontroller 130, and a suction motor 161.

Since the charger 30, the booster 140, and the suction motor 161 havethe same as those of the first embodiment, their detailed descriptionswill be omitted.

The battery 123 may include a plurality of unit cells 124 that areconnected to each other in series. The plurality of unit cells 124 maybe maintained and managed to a constant voltage by a battery managementsystem (BMS) (now shown). The battery 123 may have, for example, amaximum charging voltage of about 84.8 V or more.

The controller 130 may control an operation of the suction motor 161.Also, the controller 130 may detect an output voltage of the battery 123to allow the output of the suction motor 161 to vary. For example, thecontroller 130 may control the suction motor 161 so that the output ofthe suction motor 161 is uniformly maintained or decrease.

Also, the controller 130 may detect a voltage of the battery 123 tocontrol a voltage applied to the suction motor 161 and prevent thebattery 123 from increasing in temperature when the battery 123 isdischarged.

Particularly, the controller 130 may include a detection part 131 fordetecting the voltage of the battery 123 and a current adjustment part132 that adjusts the current of the battery 123 to adjust currentapplied to the suction motor 132.

The suction motor 161 may have a maximum output of about 600 W or more,but is not limited thereto.

Hereinafter, a method of controlling the vacuum cleaner will bedescribed.

FIG. 4 is a flowchart for explaining a method of controlling the vacuumcleaner according to the second embodiment.

Referring to FIG. 4, when a cleaning start command is inputted into thevacuum cleaner, a voltage of the battery 123 is supplied to the suctionmotor 161, and thus, the suction motor 161 operates.

Hereinafter, although not limited, it is assumed that the battery 123has a maximum charging voltage of about 92.4 V, and the suction motor160 has a maximum output of about 680 W.

Then, in operation S1, the voltage of the battery 123 is detected by avoltage detection part 131 of the controller 130.

In operation S2, the controller 130 may determine whether the voltage ofthe battery, which is detected by the voltage detection part 131, isabove a first reference voltage.

The first reference voltage may be less than a maximum charging voltageof the battery 123, for example, about 85 V, but is not limited thereto.

According to the result determined in the operation S2, if the voltageof the battery, which is detected by the voltage detection part 131, isabove the first reference voltage, the controller 130 may adjust anoutput of the suction motor 161 so that the suction motor 161 operatesat a first reference output for a first reference time. Particularly,since a current adjustment part 132 adjusts current inputted into thesuction motor 161, an output of the suction motor may be maintained tothe first reference output in operation S3. Here, the first referenceoutput may be a maximum output of the suction motor 161.

In general, if a temperature of the battery 123 becomes to a referencetemperature (example, about 55 degrees, but is not limited thereto) whenthe battery 123 is discharged, the battery 123 may not be charged by aprotection circuit disposed in a battery management device until thetemperature of the battery 123 is lower than the reference temperatureregardless of a residual changing amount of battery 123. In this case,to charge the battery 123, the battery 123 has to stand by until thetemperature thereof decreases. Thus, a charging time of the battery 123may increase.

Thus, to prevent the charging time of the battery 123 from increasing,it may be necessary to restrict the temperature of the battery 123.

Also, although not limited, when the current of the battery 123 is aboveabout 1 A, possibility in which the temperature of the battery 123exceeds the reference temperature may be high.

In the current embodiment, when the voltage of the battery 123 is abovethe first reference voltage, input current of the suction motor 161 maybe adjusted so that the suction motor 161 operates at the firstreference output.

For example, when the battery 123 is charged to have the maximumcharging voltage, the battery 123 may have an initial voltage of about92.4 V. In this case, to allow the suction motor 161 to realize anoutput of about 680 W, current inputted into the suction motor 161 maybe about 7.36 A.

Also, when the suction motor 161 continuously operates, the voltage ofthe battery 123 may decrease. For example, when the voltage of thebattery 123 is lowered to about 88 V that is higher than the firstreference voltage, the current inputted into the suction motor 161 maybe maintained to about 7.36 A, and the output of the suction motor 161may be reduced to about 647 W.

However, in the current embodiment, the current adjustment part 131 mayincrease the input current of the suction motor 161 to allow the outputof the suction motor 161 to be maintained to the first reference output.

However, when the voltage of the battery 123 reaches about 85 V that isthe first reference voltage, the input current of the suction motor 161may become to about 8 V so that the output of the suction motor 161becomes to the first reference output.

As described above, when the input current of the suction motor 161 isabout 8 V, the temperature of the battery 123 may exceed the referencetemperature.

Thus, if the voltage of the battery 123 is less than the first referencevoltage in the current embodiment, the input current adjustment of thesuction motor 161 may be stopped.

Particularly, while the input current of the suction motor 161 isadjusted to maintain the output of the suction motor 161 to the firstreference output in operation S3, the controller 130 may determinewhether the voltage of the battery 123 is less than the first referencevoltage before the first reference time elapses in operation S4.

According to the result determined in the operation S4, if the voltageof the battery 123 is less than the first reference voltage before thefirst reference time elapses, the controller 130 may stop the inputcurrent adjustment of the suction motor 161 at a time point at which thevoltage of the battery 123 is less than the first reference voltage inoperation S5.

Also, according to the result determined in the operation S4, if thevoltage of the battery 123 is not less than the reference voltage beforethe first reference time elapses, the controller 130 may determinewhether the first reference time elapses in operation S6.

According to the result determined in the operation S6, if it isdetermined that the first reference time elapses, the controller 130stops the input current adjustment of the suction motor 161 in operationS7.

As described in the operation S5 or S7, when the input currentadjustment of the suction motor 161 is stopped, the voltage of thebattery 123 may decrease to reduce the output of the suction motor 161.

In operation S8, the controller 130 determines whether the voltage ofthe battery 123 is a second reference voltage, and the output of thesuction motor 161 reaches a second reference output that is less thanthe first reference output.

Also, according to the result determined in the operation S2, when thevoltage of the battery 123 is less than the first reference voltage, theprocess proceeds to operation S8.

Although not limited, in this specification, the second referencevoltage may be about 66 V, and the second reference output may be about400 W.

Of cause, the controller 130 may determine only whether the output ofthe suction motor 161 reaches the second reference output that is lessthan the first reference output.

According to the result determined in the operation S8, if the voltageof the battery is less than the second reference voltage, and the outputof the suction motor 161 reaches the second reference output that isless than the first reference output, the controller 130 may control theoutput of the suction motor 161 so that the output of the suction motor161 is maintained to the second reference output. Particularly, inoperation S9, the controller 130 may adjust the input current of thesuction motor 161 to control the output of the suction motor 161.

Also, when the voltage of the battery 123 reaches a third referencevoltage (a limit voltage) that is less than the second referencevoltage, the controller 130 may stop the operation of the suction motor161 and allow an alarm part (not shown) to generate charging requestinformation of the battery. Although not limited, the third referencevoltage may be about 50 V.

According to the proposed embodiment, when the voltage of the battery123 is above the first reference voltage, since the current of thesuction motor is adjusted so that the output of the suction motor 161 ismaintained to the first reference output, a state in which a outputforce of the suction motor is maximized may be maintained.

Also, if the voltage of the battery 123 is less than the first referencevoltage, or a current adjustment time elapses the first reference time,the input current adjustment of the suction motor 161 may be stopped toprevent the temperature of the battery 123 from exceeding the referencetemperature.

Also, when the output of the suction motor 161 reaches the secondreference output that is less than the first reference output, thecontroller 130 adjusts the input current of the suction motor 161 sothat the output of the suction motor 161 is maintained to the secondreference output. Thus, the output of the suction motor 161 may becontinuously reduced to prevent the suction force from beingcontinuously reduced, thereby continuously performing the cleaning untilthe charging of the battery is required.

The adjustment of the output of the suction motor by using thecontroller described in the current embodiment may be equally applied tothe first embodiment. Here, the battery according to the currentembodiment may correspond to the first battery according to the firstembodiment, and the suction motor according to the current embodimentmay correspond to the suction motor constituting the first driving partaccording to the first embodiment.

At least one of the first to third reference voltages and the first andsecond reference outputs may vary according to the maximum chargingvoltage of the battery and the maximum output of the suction motor.

FIG. 5 is a perspective view of a vacuum cleaner according to a thirdembodiment, and FIG. 6 is a block diagram of the vacuum cleaneraccording to the third embodiment.

Referring to FIGS. 5 and 6, a vacuum cleaner 1 according to the currentembodiment may include a cleaner body 10 including a suction motor 161for generating a suction force and a suction device 20 for guiding aircontaining dusts to the cleaner body 10.

The suction device 20 may include a suction part 21 for suctioning dustsdisposed on a surface to be cleaned, for example, a bottom surface andconnection parts 22, 23, and 24 for connecting the suction part 21 tothe cleaner body 10.

The connection part 22, 23, and 24 may include an extension tube 24connected to the suction part 21, a handle 22 connected to the extensionpart 24, and a suction hose 23 connecting the handle 22 to the cleanerbody 10.

Also, the vacuum cleaner 1 may further include a dust separation part(not shown) for separating dusts from air suctioned by the suctiondevice 20 and a dust container 110 for storing the dusts separated bythe dust separation part. The dust container 110 may be separablymounted on the cleaner body 10. The dust separation part may be providedas a separate part that is separated from the dust container 110 or beprovided as one module together with the dust container 110.

The vacuum cleaner 1 may include a battery 123 supplying a power foroperating the suction motor 161, a charger 180 for charging the battery123, and a power cord 40 separably connected to the cleaner body 10 andsupplying a commercial power into the cleaner body 10.

The power cord 40 may include a plug 41 connected to a socket and afirst connector 42 connected to the cleaner body 10. Also, the cleanerbody 10 may include a cleaner connector 102 connected to the firstconnector 42.

The battery 123 may include a plurality of unit cells 124 that areconnected to each other in series. The plurality of unit cells 121 maybe maintained and managed to a constant voltage by a battery managementsystem (BMS) (now shown). The battery 123 may have, for example, amaximum charging voltage of about 84.8 V or more.

The charger 180 may perform rectification and smoothing operations toconvert a commercial AC voltage into a DC voltage. Also, the charger 180may supply the converted DC voltage to the battery 123. For example, thecharger 180 may convert a commercial AC voltage of 42.4 V into a DCvoltage that exceeds about 42.4 V to supply the converted DC voltage tobattery 123.

The charger 180 may be disposed on the cleaner body 10, the suction part21, or the handle 22.

The charger 180 may include a transformer 181 for converting theinputted AC voltage and an AC-DC converter 182 for converting an ACvoltage outputted from the transformer 181 into a DC voltage. Here, theDC voltage outputted from the AC-DC converter 182 may exceed about 42.4V.

For another example, the DC voltage outputted from the AC-DC convertermay be converted by the transformer. In this case, a DC voltageoutputted from the transformer 181 may exceed about 42.4 V.

For another example, the charger 180 may not include the transformer,and the AC-DC converter 182 may include a circuit for preventing the DCvoltage from being converted into the AC voltage. That is, the AC-DCconverter 182 may be an isolated converter. In the current embodiment,since the wall-known converter is used as the AC-DC converter, detaileddescription thereof will be omitted.

In the current embodiment, the suction motor 161 may be, for example, aBLDC motor. Also, the suction motor 161 may have a maximum output ofabout 600 W or more, but is not limited thereto.

Since the high-output suction motor 161 is used in the currentembodiment, the suction force of the cleaner may increase.

Also, in the current embodiment, the controller 130 may perform the samefunction as that of the controller 130 according to the secondembodiment. That is, when the voltage of the battery 123 is above thefirst reference voltage, the controller 130 may adjust the current ofthe suction motor so that the output of the suction motor 161 ismaintained to the first reference output.

Also, when the voltage of the battery 123 is below the first referencevoltage, or the current adjustment time elapses the first referencetime, the controller 130 may stop the input current adjustment of thesuction motor 161.

Also, when the output of the suction motor 161 reaches the secondreference output that is less than the first reference output, thecontroller 130 may adjust the input current of the suction motor 161 sothat the output of the suction motor 161 is maintained to the secondreference output.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A vacuum cleaner comprising: a cleaner bodycomprising a suction motor to generate suction; a suction part tocommunicate with the cleaner body to suction air and dust particles; atleast one battery disposed on the cleaner body or the suction part tosupply power to the suction motor; and a controller to control anoperation of the suction motor, wherein the controller controls anoutput of the suction motor according to an output voltage of the atleast one battery.
 2. The vacuum cleaner according to claim 1, whereinthe controller controls the output of the suction motor so that theoutput of the suction motor is uniformly maintained for a predeterminedtime even though the output voltage of the at least one battery isreduced.
 3. The vacuum cleaner according to claim 2, wherein thecontroller controls the output of the suction motor so that the suctionmotor operates at a first reference output when the output voltage ofthe at least one battery is above a first reference voltage.
 4. Thevacuum cleaner according to claim 3, wherein the controller comprises: avoltage detection part to detect the output voltage of the at least onebattery; and a current adjustment part to adjust an input current of thesuction motor so that the suction motor operates at a first referenceoutput when the output voltage of the at least one battery is above afirst reference voltage.
 5. The vacuum cleaner according to claim 4,wherein the current adjustment part increases the input current of thesuction motor in response to a reduction of the output voltage of the atleast one battery.
 6. The vacuum cleaner according to claim 4, wherein,when the output voltage of the at least one battery is less than thefirst reference voltage before a first reference time has elapsed froman input current adjustment start time of the suction motor, thecontroller stops the current adjustment through the current adjustmentpart at a time when the output voltage of the at least one battery isless than the first reference voltage.
 7. The vacuum cleaner accordingto claim 4, wherein the controller stops the current adjustment throughthe current adjustment part when a first reference time has elapsed froman input current adjustment start time of the suction motor.
 8. Thevacuum cleaner according to claim 3, wherein the controller determineswhether the output of the suction motor reaches a second referenceoutput that is less than the first reference output when the outputvoltage of the at least one battery is less than the first referencevoltage, and wherein the controller controls the output of the suctionmotor so that the output of the suction motor is maintained at thesecond reference output when the output of the suction motor reaches thesecond reference output.
 9. The vacuum cleaner according to claim 8,wherein the controller comprises a current adjustment part to adjust aninput current of the suction motor so that the output of the suctionmotor is maintained at the second reference output.
 10. The vacuumcleaner according to claim 8, wherein, when the output voltage of the atleast one battery reaches a limit voltage while the suction motor ismaintained at the second reference output, the controller stops theoperation of the suction motor.
 11. The vacuum cleaner according toclaim 1, wherein the at least one battery comprises: a first batteryhaving a first maximum charging voltage; and a second battery having asecond maximum charging voltage, wherein the suction motor receivespower from the first battery.
 12. The vacuum cleaner according to claim11, wherein the controller controls the output of the suction motoraccording to an output voltage of the first battery.
 13. The vacuumcleaner according to claim 11, further comprising a driving partconnected to the second battery and switched from an off state to an onstate, or from the on state to the off state, while the suction motoroperates.
 14. The vacuum cleaner according to claim 1, furthercomprising: a charger separably connected to the cleaner body or thesuction part to charge the battery; and a booster that increases avoltage outputted from the charger to supply the increased voltage tothe at least one battery.
 15. The vacuum cleaner according to claim 1,further comprising: a power cord separably connected to the cleaner bodyor the suction part to supply power to the cleaner body or the suctionpart; and a charger disposed on the cleaner body or the suction part tocharge the at least one battery.
 16. A vacuum cleaner comprising: acleaner body; a suction part to communicate with the cleaner body tosuction air and dust particles; a first battery disposed on the cleanerbody or the suction part, the first battery having a first maximumcharging voltage; a second battery disposed on the cleaner body or thesuction part, the second battery having a second maximum chargingvoltage that is less than the first maximum charging voltage; a firstdriving part to receive power from the first battery; and a seconddriving part to receive power from the second battery.
 17. The vacuumcleaner according to claim 16, wherein the second driving part isswitched from an off state to an on state, or from the on state to theoff state, while the first driving part operates.
 18. The vacuum cleaneraccording to claim 16, wherein the first driving part comprises asuction motor to generate suction.
 19. The vacuum cleaner according toclaim 16, further comprising: a charger separably connected to thecleaner body or the suction part to charge the first and secondbatteries; and a booster that increases a voltage outputted from thecharger to supply the increased voltage to the first battery.
 20. Thevacuum cleaner according to claim 19, wherein the booster comprises aboost converter.